package com.example.contactstest;

import android.Manifest;
import android.content.pm.PackageManager;
import android.database.Cursor;
import android.provider.ContactsContract;
import android.support.annotation.NonNull;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    ArrayAdapter<String> adapter;
    List<String> contactsList=new ArrayList<>();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ListView contactsList=findViewById(R.id.contacts_view);
        adapter=new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1, (List<String>) contactsList);
        contactsList.setAdapter(adapter);
        if(ContextCompat.checkSelfPermission(this,Manifest.permission.READ_CONTACTS)!= PackageManager.PERMISSION_GRANTED){
            ActivityCompat.requestPermissions(this,new String[]{Manifest.permission.READ_CONTACTS},1);
        }else{
            readContacts();
        }
    }

    private void readContacts() {
        Cursor cursor=null;
        try{
            cursor=getContentResolver().query(ContactsContract.CommonDataKinds.Phone.CONTENT_URI,
                    null,null,null,null);
            if(cursor!=null){
                while (cursor.moveToNext()){
                    String displayName=cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
                    String number=cursor.getString(cursor.getColumnIndex(ContactsContract.CommonDataKinds.Phone.NUMBER));
                    contactsList.add(displayName+"\n"+number);
                }
                adapter.notifyDataSetChanged();
            }
        }catch (Exception e){
            e.printStackTrace();
        }finally {
            if(cursor!=null){
                cursor.close();
            }
        }

    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        switch (requestCode){
            case 1:
                if(grantResults.length>0&&grantResults[0]==PackageManager.PERMISSION_GRANTED){
                    readContacts();
                }else{
                    Toast.makeText(this,"you denied the premission",Toast.LENGTH_SHORT);
                }
                break;
                default:
        }
    }
}
